A perilla, which is one of representative oilseed crops in Korea, is a perennial plant belonging to the family Lamiaceae. It is originated in southeast Asia including Korea, and has been widely used as a food such as health food, hypertension prevention food as well as simple edible food.
The use of the perilla in Korea is recorded in the unified Silla period with sesame seeds. It grows easily at the foot of a mountain of the country or at wetlands along the roadside, and is distributed everywhere in the country.
The perilla has the three major nutrients, which are 45% fat, 18% protein, and 28% carbohydrates, and has been used for many years as an important maintainer.
The method of extracting the perilla oil from the perilla includes various extracting method such as a roasting and heat pressing method, in which the perilla is roasted and pressed, a supercritical extraction method, in which high-priced machines are used to extract by solvent, a cold pressede method using an oil expression without roasting the perilla, in which the perilla is dried and then oil-expressed as it is, thereby producing the perilla oil through the precipitating and filtrating steps. However, the supercritical extraction method suffers a lot of rejection from consumers due to the risk of solvent. Also, in case of the cold pressede method, the flavor of the perilla oil is relatively lower than that of the roasting and heat pressing method. Accordingly, most of the perilla oils are produced by the roasting and heat pressing method.
The roasting and heat pressing method is a method of producing perilla oil by roasting perilla seeds at high temperature (160 to 230° C.). There is a problem that substances such as benzophene are detected. Also, since the supercritical extraction method can be rapidly and selectively extracted, there is no risk of a residual harmful solvent and it is possible to extract a substance sensitive to heat such as a natural product or food. However, it is not realistic because the production cost is very high.
The perilla oil extracted from the perilla contains about 35% to 46% of fatty acids, about 10% of saturated fatty acids, and about 90% of unsaturated fatty acids, 60% of which are n−3 unsaturated fatty acids. It is known that the perilla has a physiological action effective in the prevention of adult diseases such as an improvement of hardening of arteries and high blood, a change in the quality of the stiff tissue, drop in blood pressure, an improvement of thrombosis, an inhibition of cancer cell growth, an improvement of learning ability, a brain development, improvement of allergic constitution, and a life extension and so on. Accordingly, the value of use thereof is growing more and more.
Accordingly, the techniques of Patent Literatures 1 to 4 have been proposed for producing the perilla oil.
The Patent Literature 1 relates to a method for preparing an oil product by using powdered sesame seed and perilla seed including steps of sorting and pulverizing sesame seed and perilla seed; mixing 20 wt % of the finely powdered sesame seed and 5 wt % of the powdered perilla seed with 75 wt % of cooking oil made from corn; extracting the mixture at 190° C. for 60 mins and first filtrating the extract with a separator to remove the solid from the mixture; and then secondary filtrating the resulting liquid by using a filter press and adding 0.03 wt % of Polyphenox to the completely filtrated liquid of oil. The method has an effect of serving the oil having unique taste and aroma of the sesame and the perilla at the same time.
Patent Literature 2 relates to a method of manufacturing edible plant oil and an edible plant oil manufactured by using the same, in which saturated fatty acid is removed by subjecting edible vegetable oil to chemical treatment to remove saturated fatty acid and reconstituting with unsaturated fatty acid is provided. The edible oil contains useful components for the body and is beneficial to human body. First, edible vegetable oil is trans-esterified with C1-8 alkanol in the presence of C1-8 alkoxide catalyst of alkali or alkaline earth metals, neutralized with organic acid or inorganic acid and removed in the alkanol to produce an alkyl ester mixture of saturated and unsaturated fatty acid. Second, the alkyl ester mixture of saturated and unsaturated fatty acid is reacted with urea dissolved in C1-8 alkanol to remove a complex of fatty acid alkyl ester and urea. Then 3 mol of the separated unsaturated fatty acid alkyl ester is mixed with triglyceride comprising C1-8 low molecular weight fatty acid and trans-esterified with C1-8 alkanol in the presence of C1-8 alkoxide catalyst of alkali or alkaline earth metals.
Patent Literature 3 relates to a fresh perilla seed oil and a method for manufacturing the same. The method for manufacturing fresh perilla seed oil according to an embodiment of the present invention includes a washing step of washing perilla seeds with water and draining the same; a cold air drying step of drying the washed perilla seeds with a cold wind of 15-20° C.; an oil expression step of wrapping the dried perilla seed in a mesh cloth and applying pressure to the same at 15-20° C. so as to collect fresh perilla seed oil; and refining step of letting the expressed fresh perilla seed oil stand at 5-10° C. There are effects having a high extraction yield and excellent quality.
Patent Literature 4 relates to a method for manufacturing sesame oil or perilla seed oil according to the present invention including a washing step (S100) of removing remaining pesticides or foreign substances adhered to the surface of sesame seeds or perilla seeds by a mixed solution in which sodium hydrogen carbonate is dissolved; a dehydrating step (S200) of removing purified water and drying the surface of the sesame seeds or perilla seeds, after washing the surface using the mixed solution; a roasting step (S300) of roasting the sesame seeds or perilla seeds dried after the purified water is removed; an oil extracting step (S400) of extracting oil from the roasted sesame seeds or perilla seeds using an oil expression; a purifying step (S500) of mixing the extracted sesame oil or perilla seed oil with hardwood activated charcoal powder, and purifying the same by a filter to manufacture the purified sesame oil or perilla seed oil; and a packing step (S600) of packing the purified sesame oil or perilla seed oil into a predetermined amount to complete the manufacturing process of the purified sesame oil or perilla seed oil. In the washing step (S100), a bamboo salt powder in addition to the sodium hydrogen carbonate is further mixed to produce the mixing solution. At this time, it is mixed in a weight ratio of 50 to 60 parts of sodium hydrogen carbonate and 5 to 10 parts of bamboo salt powder and the sodium hydrogen carbonate and the bamboo salt powder are pulverized in a particle size of 50 to 100 μm by using a mill.
On the other hand, the perilla oil as the edible oil contains a variety of fats, sterols, monoterpenes, tocopherols, polyphenol compounds and the like. Especially, since α-linolenic acid, which is a highly unsaturated fatty acid, is the main component, there is a problem in that it is easily acidified. Accordingly, the usability thereof is extremely limited.
Therefore, since the perilla oil is easy to oxidize and the shelf life thereof is short, it is recommended to consume as quickly as possible after opening and the refrigeration thereof is recommended during storing.
However, since the perilla oil contains various fatty acids, during storing at low temperature or in a refrigerator, the perilla oil is solidified, so that white spots or white precipitates are formed.
As a part of this, in the perilla oil distributed in and out of the country, the perilla oil product (DL) having caution statements “freezing coagulation phenomenon (occurrence of white spots or precipitates) is generated during winter, low temperature, or refrigeration storage, but there is no abnormality in the product” can be easily found. This is to prevent the consumer from having a negative perception on the problem caused by the above-mentioned perilla oil coagulation phenomenon. However, it does not solve the fundamental problem on the occurrence of the floating matter owing to the freezing coagulation phenomenon generated in the perilla oil.
That is, in the perilla oil, α-linolenic acid, which is often referred to as omega-3 fatty acid, is contained as a major component in an amount of about 60%. However, since this is a component that is susceptible to rancidity, it is required to be stored in a refrigerator. In case of the oil expression through a heating treatment at high temperature, since carcinogens such as benzopyran and trans fatty acids are produced, it is necessary to process, express, and store it in accordance with the characteristic of the perilla oil. However, due to the inability to perform such process in harmony, peoples are not able to get the perilla oil, which is an excellent plant oil, properly. Also, during the cold storage for preventing rancidity, it causes inconvenience to those who ingest it, because of the floating matter produced by the low temperature.
In the Patent Literature 1, after the finely powdered sesame seed, the perilla seed, and the cooking oil made from corn are mixed to express oil, it is first filtrated through the centrifugal separator and then secondary filtrated through the filter press to manufacture the final product. Accordingly, it has unique taste and aroma of the sesame and the perilla at the same time. However, since it is extracted at a high temperature of 190° C., the trans fatty acids and the carcinogenic substances such as benzopyran are produced. Also, in order to delay the rapid rancidity due to the characteristics of α-linolenic acid, the refrigeration storage is essential. However, during refrigeration storage, since various fatty acids contained in the perilla oil has different melting points, even if the primary and secondary filtration processes are carried out, the floating matters are produced, which causes people who ingest them to feel uncomfortable.
The Patent Literature 2 is constructed so as to provide the edible vegetable oil which is obtained by removing a saturated fatty acid and reconstituted with only the unsaturated fatty acid through the chemical treatment step. However, in the perilla oil manufactured by the Patent Literature 2, in order to delay the rapid rancidity due to the characteristics of α-linolenic acid, the refrigeration storage is also essential. However, during refrigeration storage, since various fatty acids contained in the perilla oil has different melting points, even if the primary and secondary filtration processes are carried out, the floating matters are produced, which causes people who ingest them to feel uncomfortable. According to the method for manufacturing the perilla oil as described in Example 8, it heats and processes at a high temperature of 105° C., Accordingly, there arises a problem that the trans fatty acid is generated and the carcinogenic substance such as benzopyrene is produced. Therefore, in the manufacturing method of the Patent Literature 2, it does not meet the characteristics of the perilla oil.
In the Patent Literature 3, it is refined only by a process of standing at a temperature of 5 to 10° C. and is subjected to the refining process without a separate filtration process so as to realize the clean state. However, as a result of the fact that those skilled in the art have accomplished this, it has been found that there is almost no other residue at the stage of standing at a temperature of 5 to 10° C. However, when it stores for about 10 hours or more in the refrigerator, it was confirmed that the floating matters were generated similarly to the conventional perilla oil. Also, the amount of the floating matters was slightly smaller than that of the conventional perilla oil when visually confirmed. However, as can be seen from the sensory evaluation described in the following description, it was confirmed that the perilla oil is pretty much the same as the conventional perilla oil, which is mainly due to the different melting points of the various fatty acids contained in the perilla oil. Accordingly, there is a problem that it causes people who ingest them to feel uncomfortable. Also, there is a problem in that the flavor and aroma thereof are relatively lowered due to the unroasted raw perilla produced by the oil expression.
In Patent Literature 4, after mixing the expressed perilla seed oil with the hardwood activated charcoal powder, it purifies the same by the filter so as to remove odor contained in the perilla oil. Accordingly, it provides sterilized perilla oil with good flavor, so that it can provide the perilla oil capable of delaying the rancidity thereof. However, the delay of the rancidity is only a temporary delay of rancidity due to the temporary sterilization of germs contained in the perilla oil. Accordingly, when the cold storage and the refrigeration storage not accompanied, since the rancidity thereof is much faster than that in the refrigeration storage, the refrigeration storage is essential. However, during refrigeration storage, since various fatty acids contained in the perilla oil has different melting points, even if the primary and secondary filtration processes are carried out, the floating matters are produced, which causes people who ingest them to feel uncomfortable. According to <3. roasting step (S300)> below a paragraph number [0054] of the Patent Literature 4, the perilla is put into a high-temperature roasting oven maintained at a temperature of 310° C. and roasted at a temperature of 190° C. to 230° C. At this time, since there arises a problem that the trans fatty acid is generated and the carcinogenic substance such as benzopyrene is produced, in the manufacturing method of the Patent Literature 4, it does not meet the characteristics of the perilla oil.